Severe Aortic Regurgitation in Osteogenesis Imperfecta Complicated by Mediastinal Hematoma

BACKGROUND: Osteogenesis imperfecta (OI), a heritable type I collagen disorder, can cause aortic regurgitation (AR) and increase perioperative bleeding risk, even with normal routine coagulation tests. CASE SUMMARY: A man in his 40s presented with AR due to right coronary cusp prolapse from cusp bending. Blue sclera and childhood fractures suggested OI. After an attempted repair, surgical aortic valve replacement was performed; a large postoperative mediastinal hematoma with anemia was managed conservatively without reoperation. DISCUSSION: A prior report identified cusp bending in OI mainly by imaging. Our case complements histopathology showing marked fibrosa thinning with spongiosa expansion, which suggests intrinsic leaflet fragility as a substrate for bending and prolapse. It reminds readers that postoperative bleeding can occur despite normal coagulation parameters. TAKE-HOME MESSAGES: In young patients with unexplained AR, especially with cusp bending, OI and related connective tissue disorders should be considered. Perioperative care with heightened vigilance for bleeding is planned.